Concentration of ores



Patented Oct. 29, 1935 UNITED STATES PATENT OFFICE- aoiasoc v CONCENTRATION OF OBES cm; s. may. xenon. Idaho at Drawing. Application July 18, 19:4, Serial No. 135,882

8 Claiml. (Cl. 209-167) This invention relates to improvements in the concentration of finely divided ores, by flotation, and has to do with an improved method. Ore prepared for flotation treatment contains 3 what I will term natural colloidal matter", which vention is a term of depressant which, in an altered pulp, functions to depress all of the mineral rticles and also render them susceptible of being selectively floated and frothe'd oil, as a result a of the reaction of certain conditioning agents, whereby in a continuous process of recovery from one. pulp, I can recover each of the several 5111- phidcs in commercial quantity and in a rapid and emcient manner.

In one phase of the invention, the depressant is in the form of an artificial colloidal substance" which is deflnable'and definite, and which I can selectively use, and which therefore eliminates the indefinable, indefinite and quantity-uncertain conditions inherent in the natural colloidal matterthat is removed from the ore.

Hy reason 'of this artificial depressant, I-am able, with certain conditioning agents, selectively to'fioat and froth the several sulphides, and after these sulphides have been recovered, I am able to float and iro'th oxide ore particles by reason of a novel conditioning compound; the entire processor recovery being completed in the altered pulp which I form after the natural colloidal -tter has been removed.

invention therefore involves the followin The natural colloidal matter is first removed from the normal pulp, if present, and this may be accomplished by adding ade-flocculating agent to separate the natural colloidal matterfrom the crystalline matter by deflocculation and then removing such colloidal matter by any well known means such as filtration, decantation, elutriation or centrifugal force, in a. manner clearly disclosed in myprior-patent issued December 3, 1939, No. 1,737,716. Water is then. added to the crystallinematter to iorm a de-flocculated pulp and my artificial colloidal depressant is introduced into the deflocculated pulp, in the presence of agitation, and iunctions to sink the sulphide ore particles in the pulp. A frothing agent is next introduced and if no minerals arise, the efiiciency of the depressant is proven.

A conditioning agent is then added which functions with the artificial depressant in a manner to float and froth the galena concentrate, and the same is then removed. However, this recovery of the galena concentrate does not interfere with the action of the depressant in inhibiting the sphalerite from floating.

I next introduce a diiferent kind of conditioning agent which-functions to float and froth the sphalerite concentrate, which I then remove, and I then introduce 'afurther and diflerent conditioning agent which functions with the depressant to float and froth the pyrite concen trate, which I then remove. It will be understood that when I speak of galena, sphalerite and pyrite concentrates, I am speaking of concentrates of commercial purity, as shown by the assay hereinafter appended.

WhileI have stated the method steps-in the particular order, and oh the particular sulphide minerals, in which I first proved them by actual test, I have'since proven to my own satisfaction that I can selectively float other sulphide minerals in any desired order, and in thesame manne hence the feature of selectivity is not, confined to the precise order of s eps herein recited, as

this order is merely one way in which the method can be carried out. 7

The remaining pulp, containing the oxide ore particles, isthen agitated and I introduce into the pulp my conditioning compound, which also functions as a frdthing agent. This compound 35.

is in the nature of a conditioning agent and functions to activate and float the oxide ore particles such for instance as scheelite, cerussite, hematite, siderite and malachite.

' It will thus be understood that my invention, 40

as a method, involves the separation and recovery or various sulphides, and the flotation and recovery of various oxides, as two broadly distinct steps, as the oxides cannot be e'fllciently recovered'withoutflrst removing the natural colloidal matter, and the oxides cannot be efllclently recovered until after the sulphides have been frothed off. I-Ience, it will be understood that the oxidesremain inert until my combined conditioning and frothing compound has been introduced. However, itwillbe clear that I perform all of these recovery steps ,in the one single pulp. I will next give a specific example of one of the most approved ways in which my method canbe carried out.

A sample of cln'rent mill-feed of a lead-zinc, which is an extremely complex ore, was ground ore with water in a laboratory rodmill to pass one hundred mesh, and the ground pulp was diluted with water and deflocculated by the addition of sodium silicate to the pulp in the proportion of 2 lbs. per ton of ore. The liquid containing the natural colloidal matter thus separated from the crystalline matter in this normal pulp was removed by decantation and the residual crystalline matter was diluted to 40% solids, with water to form a deflocculated pulp. V

I next introduced into the laboratory flotation ly prepared consisting of the following ingredients:

Percent by weight Oleic acid 57.17 5 Cresylic a 28.7 Soda ash 7.7 Sodium silicate 7.7

may Percent total 15 Per- Product cent r Peh rcent cent cent Lead Zinc Iron Pb. Zn. Fe

. 20 Feed- 100. 0 4. 0 7. 0 14. l 100. 0 1m. 0 1m. 0 Lead OOIlOt- 11.0 L0 9.0 2L0 82.5 14. 1 18.7 Lead rgh. 89.0 0.8 6. 3 13.0 17. 5 85. 9 Bl. 6 Zinc nnnot 12. 0 2. 6 40. 5 1L 0 7- 9 70. I 0. Zinc l'gh. 77. 0 0. 5 0. G 13. 2 9. 0 0. 6 72. U Pyrite mnot 10.1 1.5 2.0 40.0 3.8 2.9 39.0 sulphide rgh, tailinv 07. 1 0. 4 0. 4 9. 2 5. 3 3. 7 43. U 25 Siderite 11.0 1.0 0.5 44.0 2.8 0.8 .4 Taili 66.1 0.2 0.3 2.2 3.0 2.9 8.!

machine, in the presence of agitation, my artificial improved colloidal depressant which, in this instance, was in the form of a liquid commercial glue, the proportion being 0.3 lb. of glue per ton of ore.

To the best of my knowledge and belief, the action of this artificial depressant may be in accord with either one of two theories. It may be adsorbed on the crystal faces of the sulphide ore particles to form a wettable film which causes the particles to sink, and/or this depressant may function to modify the electrical charge on the sulphide ore particles to cause them to repel one another and disperse, or be dispersed, in the pulp. Irrespective of the precise manner in which it functions, I have conclusively proven' that this depressant actually functions to cause the sulphide ore particles to sink in the pulp.

I next introduce afrothing agent consisting of .03 lb. per ton of a mixture of 10% pine oil and 90% of Barretts creosote and this formed a bright, brittle froth but no minerals arose on the froth. This proved the efficiency of my depressant. In fact, I have found this depressant to be the most efficient and positively acting depressant in resisting the action of a frothing' agent, that I have ever used.

I next introduced a conditioning agent which consisted of .005 lb. per ton of ethyl xanthate,

which produced a bright, clean froth of galena concentrate containing a minimum of sphalerite, which clearly proved that the action of the artificial colloidal depressant had inhibitedthe tendency of the sphalerite and pyrite to float. I then removed the galena froth.

-1 next introduced a conditioning agent which consisted of 1 lb. per ton of copper sulphate and a collecting agent, consisting of 0.1 lb. per ton of Barretts creosote, in thepresence of agitation,

and a bright, clean froth of sphalerite concen- While the oxide conditioning-frothing compound, previously set forth, is useful irrespective of the particular percentages, I have found in actual practice that it is far more efllcient if compounded in the manner which I will now set forth. The cresylic acid and oleic acid are mixed together and I next stir slowly into this mixture a ten percent solution of soda ash in water. If the soda ash solution is added too rapidly, the whole compound will froth badly. I next stir in a ten percent solution of sodium silicate in water, which forms an amber jelly, the latter being the P reagent. I use this reagent in a ten percent emulsion in water, for convenience.

It is desired to emphasize the fact that my artificial depressant acts, in a de-fiocculatedpulp, with extreme rapidity whereas standard depressants, as far as known to me, require a very considerable time period in which to act. For instance, in my use of this artificial novel depressant, it has acted in a period of contact of not more than one minute, while many standard depressants require a period of contact of as much as an hour. In addition to its quick acting qualities, it is an extremely low cost depressant.

WhileIhavestatedthatthisartificialdepressant may consist of commercial glue, I wish to state that I consider starch, sodium silicate, gum arabic and glucose, and many other colloidal substances as an operative equivalent or glue.

Throughout the specification and claims, wherever 1 have used the phrase artificial colloidal substance" or, artificial colloid or "artificial depressant", I mean to designate any colloidal substance not naturally present in theore, and

uralcolloidalmatterbyaddingsde-flocculatmg to permit the depressed particles to be subsequently acted upon and rendered floatable by the respective conditioning agents, whereby the one may be selectively floated.

2. In a method of concentrating difle'rent kinds of finely divided ore by floatation and selectively recovering the difl'erent varieties. the steps oi substantially completely removing all of the natural colloidal matter by adding a de-flocculating agent to substantially completely release the ore from any depressing action of such matter in the subsequent pulp, adding water to the residual crystalline matter to form a de-fiocculated pulp tree from any depressant, and in adding to the de-fiocculated pulp in the presence of agitation an artificial colloidal substance in such selective quantity to definitely depress all the difierent kinds of ore particles contained in the pulp by causing said substance to become adsorbed -on the colloidal substance, and in respectively and successively removing the selected irothed ores in the particular order in which the conditioning agents have been added.

3. In a method of concentrating diilerent kinds 5 of finely divided ore by flotation and selectively recovering the diilerent varieties, the steps of substantially completely removing all the natural colloidal matter by adding a de-fiocculating agent to substantially completely release the lat- 1o ter from any depressing action of such matter in the subsequent pulp, adding water to the residual crystalline matter to form a de-fiocculated pulp free from any depressant, in adding to the defiocculated pulp in the presence of agitation an 15 artificial colloidal substance in such selective quantity to definitely depress all the dlfl'erent kinds of ore particles contained in the pulp by causing said substance to become adsorbed on the ore particles and depress the same by alter- 20 ing the electric charge, adding a Irothing agent to the de-flocculated pulp, in successively adding diil'erent kinds oi. conditioning agents to the deflocculated pulp dependent upon the particular sulphid desired and thereby activate and suc- 25 cessively float such sulphide ore particles from the action of the colloidal depressant, in respectively and successively removing the selected sulphide ore particles frothed. and in adding a conditioning agent to activate and float the oxide ore particles 3 and thus separate them from the gangue, and finally removing the irothed oxide ore particles.

ROYAL B. HANDY.

CERTIFICATE OF CORREGTION.

Patent No. 2,019,306. October 29,1935.

ROYAL s. HANDY,

it is hereby certified that error appears in the printed specification of the above 'numhered patent requiring. correction as follows: Page 3, first column, line 12, claim I, for "one" read ore; and that the said Letters Patent-should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 7th day of January, A. D. 1936.

Leslie Frazer (See I Acting Commissioner of Patents: 

